FTR, Greg confirmed they built the airships.
And, I'm not convinced there's any "beating" here. I've seen WoS many times and I don't recall thinking Matau seemed surprised at the ships. I'd have to see it again... *heads off to consult the awesomesauce of Netflix*
Edit: All the Toa are helping carry the Matoran Spheres to the airships. They clearly already knew they were there, and none of the others act remotely surprised, for sure. In fact they already had a conveyor belt set up carrying many pods already up to the door, or close to it. Matau is introed sitting on one of these pods, then as it nears, he hops off. Stands for a second or two, calmly looking at the ship with an approving expression (he doesn't look surprised either, more like an artist standing back to admire his completed work IMO).
Then he says, "Woohoo! Nice ship." He doesn't say it instantly or with the emotion of surprise as you'd expect if he hadn't seen them; only after a moment's contemplation. None of this would even make sense anyways if it was just an intact airship they had found; everybody was completely used to seeing airships all over the place, especially Le-Metru. It only makes sense in fact because they had needed to build them, and if something is newly built, it's certainly open to question whether it's "nice" or not. He's saying, yes it is, and almost certainly jestingly reminding the others (none of whom have any expertise with flying vehicles) "and that's thanks to meeeee!"
His tone is clearly one of self-praise, meant to tease the others lightheartedly. (He was already in a joking mood when riding the sphere; about how everybody else was working hard. Of course, Matau is almost always in a joking mood.)
Onewa continues the jest, punching him on the shoulder, and adding, "Hey Matau, let's not crash it this time." This is clearly an allusion to the Lhikan II, which they also constructed, and then had crashed.
So you appear to have taken the completely opposite meaning from what was intended. It was likely meant to imply the ships were newly built, which readers of the books would presumably understand, but without coming right out and saying it so as not to overburden the movie plot, so those who don't read the books wouldn't need to know it; no harm if it goes over their heads.
Edit2: BTW, how the heck did we get off on this tangent?
Edited by bonesiii, Feb 12 2014 - 12:15 AM.